My engine loves high oil pressure

[userfriendly]

If we look at other hydraulic systems than in an automotive engine, there is typically a pump
that has a larger capacity that is required by the system.

In addition to the pump, there a series of checks and valves built into the hydraulic
system to control the direction of flow, volume and pressure.

We are all familiar with the engine pump by-pass and filter by-pass valves, but other
means of fluid control are available to the engine designer.

One trick is to drill small holes in pipe plugs and install them at the end of oil galleries.

Back to Newton; A fluid in motion will want to stay in motion.

That hole in the pipe plug will cut the "response time" of the fluid
for immediate lubrication in a changing environment.

Changing a T-fitting to a Y-fitting improves engine oil distribution.

Pressure relief valves may be added in other locations in an engine
besides at the pump and filter.

 

[Kiwi_ME]

Originally Posted By: used_0il
Back to Newton; A fluid in motion will want to stay in motion.
LOL, a "body" in motion ...

 

[userfriendly]

Engine re-builders usually have a choice of the stock low performance
oil pump or the factory performance offering including a relief spring
option.

The SBC for one example came in several factory dimensions and HP levels.

The same can be said for every domestic V8 since 1950.

The components used in the re-build can change the engine oil bleed-down rate.

Flat tappet lifters are available with a hole in the bottom for direct
camshaft lubrication.

Hydraulic lifters come in choices of bleed down rates.

Optional roller rocker arms and lifters have more or less oil flow through
them than conventional designs do.

The bearing clearances and crank thrust may be at the maximum for the engine.

Add everything together and the oil flow rate per revolution is increased over a stock engine.

If you were rebuilding an engine, what would you do?

Use the stock low performance oil pump or the next one up?

 

[Shannow]

So this is the basis for your hypothetical engine, that has resulted in the hypothetical oil pressures that you described ?

I'm surprised at the hypothetical oil pressures that you are getting in that instance...Farmer Brown didn't accidentally install a gallery restricter kit while he was buying everything in the Summit catalogue ???

 

[virginoil]

Originally Posted By: used_0il
Engine re-builders usually have a choice of the stock low performance
oil pump or the factory performance offering including a relief spring
option.

The SBC for one example came in several factory dimensions and HP levels.

The same can be said for every domestic V8 since 1950.

The components used in the re-build can change the engine oil bleed-down rate.

Flat tappet lifters are available with a hole in the bottom for direct
camshaft lubrication.

Hydraulic lifters come in choices of bleed down rates.

Optional roller rocker arms and lifters have more or less oil flow through
them than conventional designs do.

The bearing clearances and crank thrust may be at the maximum for the engine.

Add everything together and the oil flow rate per revolution is increased over a stock engine.

If you were rebuilding an engine, what would you do?

Use the stock low performance oil pump or the next one up?


I am confused, what is the point you are making in respect to the original posted query.

 

[virginoil]

When you start your car keep the window up the exhaust fumes seem to be having an affect.

 

[SteveSRT8]

^^Good point. Some folks love to hear themselves think out loud.

But without a doubt, even in some VERY high performance engines I have had and with a third gen machinist in the family we do NOT need a HV oil pump in all engines.

Gotta know what you're doing...

 

[SHOZ]

Would your choice of oil filter specs change with a HV pump?

 

[OVERKILL]

Originally Posted By: used_0il
Engine re-builders usually have a choice of the stock low performance
oil pump or the factory performance offering including a relief spring
option.

The SBC for one example came in several factory dimensions and HP levels.

The same can be said for every domestic V8 since 1950.

The components used in the re-build can change the engine oil bleed-down rate.

Flat tappet lifters are available with a hole in the bottom for direct
camshaft lubrication.

Hydraulic lifters come in choices of bleed down rates.

Optional roller rocker arms and lifters have more or less oil flow through
them than conventional designs do.

The bearing clearances and crank thrust may be at the maximum for the engine.

Add everything together and the oil flow rate per revolution is increased over a stock engine.

If you were rebuilding an engine, what would you do?

Use the stock low performance oil pump or the next one up?


If it is an SBF, I'll use a stock pump, which isn't "low performance" and most certainly meets the needs of an engine built with stock clearances right up to the limits of the stock block (and beyond). This has been proven many times. For an engine that is loosened up a bit and used for endurance racing or the like added volume MIGHT be needed. But it also might not.

 

[another Todd]

Originally Posted By: TallPaul
Well, what is the oil pressure in your engine?

Remember that lower oil pressure will allow more flow through the engine and bearings which also can help cooling. There is a nice balance between too high and too low.


This depends on why the pressure is low. A worn out pump, clogged pump inlet, or weak or broken bypass spring will cause lower oil pressure and less flow. A thinner oil will cause lower pressure and more flow.

 

[userfriendly]

The stock performance SBC oil pump was designed in 1953
and was the pump in the 260 CID 1955 engine.
The cars hit the show rooms in Sept 1954.

The "high performance" pumps were a factory addition
to both the SBC and BBC high performance engines.

What would be the down-side to putting the larger pump
on a rebuilt engine other than by-passing more oil
under certain conditions.

Lets take some hypothetical examples;

Engine #1 is installed in a heavy vehicle. The engine is never operated above 3,500 RPM.

Engine #2 is installed in a light vehicle. The engine is operated over 5,500 rpm once in a while.

Engine #3 has a turbo charger.

Engine #4 has a NOS kit.

Engine #5 is in an off road monster truck and is operated over 5,500 rpm from time to time.

Engine #6 is installed in a drag race car with a 6,000 stall torque converter.

Which engine would you put a stock low performance oil pump in if there was a factory
high performance pump available for two dollars more, and why?

 

[zray]

Originally Posted By: TallPaul
Well, what is the oil pressure in your engine?

Remember that lower oil pressure will allow more flow through the engine and bearings ……"


really ? next time your house is on fire, tell the fireman to turn down the pressure on their fire hoses because you want "more flow". After your house burns down from lack of enough water to put out the fire, think about it some more…..

Z.